Predation on coral spawn by planktivorous fish

Abstract

The stomach contents of three species of coral reef fish were examined for changes in diet during the annual mass spawning of scleractinian corals on the Great Barrier Reef, Australia. Acanthochromis polyacanthus, Abudefduf bengalensis (Pomacentridae), and Caesio cuning (Caesionidae) were collected before and immediately after the coral spawning to determine whether the composition of the diet changed after the mass coral spawning. The diet of Caesio cuning did not change. The stomach contents of Acanthochromis and Abudefduf showed that these fish: (1) switched from an omnivorous diet to one consisting predominantly of coral spawn, and (2) that they appeared satiated with stomachs >90% full when coral spawn was present in the water column. Fish predation during coral spawning may be an important source of larval coral mortality.